The present application relates to semiconductor device fabrication, and more particularly, to the fabrication of fin field effect transistors (FinFETs) and passive resistors on a common substrate.
Field effect transistors (FETs) utilizing semiconductor alloys such as silicon germanium (SiGe) as channel materials have exhibited increased charge carrier mobility compared to conventional silicon-based FETs. However the semiconductor alloys are typically formed as random alloys and phenomenon such as alloy scattering contributes to decreased channel mobility. In addition, and since thermal conductivity of the random semiconductor alloys is lower than that of the silicon, the heat dissipation problem in theses semiconductor alloy-based FETs becomes more serious. Therefore, there remains a need for developing semiconductor alloy-based FETs with improved charge carrier mobility and thermal conductivity.
Resistors are passive devices commonly employed in integrated circuits (ICs) for protection, operation and/or current control of electric components such as FETs in ICs. However, the resistance of the resistors tends to fluctuate with temperatures during operation; resistance fluctuation hampers the performance of IC devices. Therefore, there remains a need for developing resistors with good temperature coefficient of resistance during use.